Core Outcome Domains for Eczema – Results of a Delphi Consensus Project

Introduction

Eczema is a chronic, relapsing, inflammatory skin disorder that affects up to 20% or children and 3-5% of adults.

Many trials of treatments for eczema are published every year, but there is no consensus over the most appropriate way of measuring treatment success, and many different named (and unnamed) scales are used.

Wide variation in the use of outcome measures for assessing eczema, makes if difficult to combine trial results by meta-analysis in systematic reviews.

Core sets of outcome measures are useful for increasing clinical interpretability, preventing selective reporting bias, limiting statistical errors by reducing the number of variables to be analysed, and enabling valid pooling of results across different studies.

The first step in identifying a core set of outcome measures for use in eczema research is to establish a core set of outcome domains. In order to do this, we conducted an international Delphi consensus project.

Results

Forty-six individuals from 11 countries (81% of those invited) participated.

Of these, 100% (n = 46) and 93% (n = 43) participated in the 2nd and 3rd rounds.

Overall, 6 consumer, 32 clinical experts, 1 regulatory agency representative and 7 journal editors took part

Consensus was achieved for inclusion of symptoms, physician-assessed clinical signs, and a measurement for long-term control of flares in the core set of outcome domains for eczema trials.

For medical recordkeeping, consensus was reached to regularly monitor eczema symptoms in clinical practice.

In contrast to clinical experts, journal editors and the regulatory agency representative , the majority of patients (67%) indicated that dermatology-specific should not be included in the core set.

People with a specific interest in outcome measurement (e.g. people who had developed the scales) were not invited to participate.

Discussion

The Delphi process is a useful consensus method to define core sets of outcome domains.

Involvement of patients in the process was a key strength, but may have been limited by the relatively small number of patients / carers involved.

This project represents the first step in trying to identify a core set of outcome measures for eczema research and management.

A face-to-face consensus meeting is now required to establish the best way of measuring these outcome domains.

Such a meeting was held in Amsterdam in June 2011, at which the three core domains were confirmed and an additional domain for quality of life was added.

For further details about the progress of the HOME initiative, please see :

www.homeforeczema.org

Schmitt J*, Williams HC+ & Thomas KS + on behalf of the Harmonizing Outcome Measurements in Eczema (HOME) Delphi panel

* Medical Faculty, University of Dresden, Germany and + Centre of Evidence Based Dermatology, University of Nottingham

Aim

To develop a consensus based set of core outcome domains for eczema that can be used for controlled clinical trials, and for clinical recordkeeping.

Method

Three-stage web-based international Delphi consensus exercise conducted between June 2008 and March 2010.

Participants: 57 individuals from four stakeholder groups , and representing 13 different countries were included. These consisted of:

Consumers Clinical experts Regulatory agency representatives Journal editors.

All participants were asked to rate the importance of 19 outcome domains for eczema and to choose which domains should be included in two core sets of outcomes:

For use in clinical trials For use in medical record keeping

Participants received standardized feedback, including the group median, inter-quartile range, and previous responses, and the assessment was repeated in two subsequent rounds.

Consensus was defined a priori as at least 60% of the members of at least three stakeholder groups, including consumers, recommending domain inclusion in the core set.

ConclusionPreliminary consensus over a core set of outcome domains has been reached.

Core outcomes for eczema trials include:oEczema symptomsoPhysician-assessed clinical signsoLong-term control of flaresoQuality of Life

Core outcomes for medical record-keeping:oEczema symptoms

AcknowledgementsThis poster presents independent research commissioned by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research funding scheme (RP-PG-0407-10177). The views expressed in this poster are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.

Outcome domains considered

Clinical signs assessed by physician

Clinical signs assessed by patient

Investigator global assessment

Patient global assessment

Symptoms

Quality of life (dermatology-specific)

Quality of life (general)

Short-term control of flares

Long-term control of flares

Cost

Extent of disease

Involvement of high expression areas

Treatment utilisation

Figure: The eczema severity scales Tower of Babel